1. Field of the Invention
The field of this invention generally relates to footwear, and more particularly to an article of footwear having a multi-layered sole for stimulating circulation during forefoot intensive activities by allowing for vertical flexion and massaging the wearer's foot.
2. Background of the Invention
Indoor exercise machines are a popular and convenient way for many people to obtain or maintain cardiovascular fitness. Many of these machines, such as elliptical trainers, stair climbers, and stationary bicycles, utilize pedals that hold a user's feet stationary. As such, intense pressure is borne by the forefoot for the duration of the workout. Similar pressures are also experienced in other repetitive, forefoot intensive activities, such as step aerobics. Many users of such equipment experience pain, burning, tingling, or numbness in their feet. This phenomenon is called “transient paresthesia” (hereinafter, “TP”), also known more colloquially as “numb toe” or “sleepy feet”. While the precise mechanism for causing TP is unknown, the pressure on the nerves of the feet and the pressure causing an interruption in blood flow circulation are strongly suspected. If unrelieved for extended periods, TP may develop into a more permanent numbness in the feet. At the very least, TP often causes the user to cut short or interrupt a workout to reduce these irritating sensations in the feet.
Users who experience TP may try several methods to prevent or relieve TP. One such method is wearing shoes with very stiff soles, which help to distribute more evenly the pressures on the foot. However, such shoes can be uncomfortable for use on an elliptical trainer. Another method used is to wear shoes having particularly stiff support in the arch region of the sole, which prevents the arch from collapsing. However, such arch support is only useful in preventing or reducing TP in a small number of wearers. Finally, some users wiggle their toes, lift their heels, or otherwise move their feet to increase circulation and redistribute pressure. Such manipulation of the feet while using exercise machines is not safe, however, as the foot could slip off of a pedal or out of a strap, thereby causing potentially severe injuries to the user.
Accordingly, needed in the art is a safe way to increase the circulation and/or dynamically redistribute pressure in the forefoot during forefoot intensive activities, such as while using an exercise machine.